This application claims priority to Japanese Patent Application No. JP2001-222008, filed Jul. 23, 2001, which application is hereby expressly incorporated by reference.
The present invention relates to an electrical connection box, particularly an electrical connection box capable of increasing a degree of freedom in circuit design as well as providing flexibility to accommodate different vehicle specifications. Further, the present invention relates to a method of producing such an electrical connection box.
Vehicles carry electrical connection boxes that accommodate electric devices such as fuses, relays and diodes. These electrical connection boxes connect wire harnesses routed throughout the vehicle body. Many types of electrical connection boxes have been tailored for particular circuit design requirements for different vehicle types and specifications.
A known electrical connection box 1 is shown in FIG. 13. The electrical connection box accommodates internal circuits in upper and lower cases 1a, 1b. The internal circuits are stacked in layers, composed of a layer of single-core wires 2 routed in a predetermined configuration. A bus bar 4 is punched into a predetermined configuration. The bus bar 4 is placed on an upper surface of an insulation plate 3 which is interposed between the single-core wires 2 and the bus bar 4. The internal circuits are also composed of a printed circuit board 6 disposed above the bus bar 4. An insulation plate 5 is interposed between the bus bar 4 and the printed circuit board 6.
Connection tabs 7 make pressure grip connections with the single-core wires 2, while they are inserted into connector accommodating portions 1c provided on a lower surface of the lower case 1b. Similarly, connection tabs 4a, projecting upwardly and downwardly from the bus bar 4, and connection tabs 6a, mounted on the print circuit board 6, are inserted into the connector accommodating portions 1c as well as into electric device mounting portions 1d and connector accommodating portions 1e provided on an upper surface of the upper case 1a. Relay terminals 8 are used to electrically connect the internal circuits arranged in different layers. Electric devices such as fuses F are mounted into the electric device mounting portions 1d. External connectors, such as connectors C attached to ends of wire harnesses W/H constituting external circuits, are mounted into the connector accommodating portions. Accordingly, an electrical connection is established between the internal and external circuits.
The installation position of the electrical connection box 1 to be mounted to the vehicle body is restricted by the positions of the electric device mounting portions 1d accommodating the fuses F. The electrical connection box 1 is installed so that the electric device mounting portions 1d face toward a passenger compartment side. This mounting enables ready replacement of the fuses F, when needed. In addition, the internal circuits of the electrical connection box may be configured in a different manner. For example, the internal circuits may be composed of bus bar layers and insulation layers only, or composed of single-core wire layers and insulation layers only.
The present invention seeks to solve the following problems of the conventional electrical connection box. First, the internal circuits of the electrical connection box 1 are specially designed for a particular type of vehicle accommodating the electrical connection box 1. Also, the upper and lower cases 1a, 1b, which accommodate such internal circuits, are specially designed according to the constructions of the internal circuits as well as to the configurations of the electric devices and the external connectors of the external circuits. Thus, a different punching die, used to form a bus bar, and a different injection mold, used to produce upper and lower cases, are necessary for every different type of vehicle. Therefore, production cost is extremely high.
Moreover, even if the conventional electrical connection boxes are utilized for the same type of vehicles, since vehicle body portions and components mounted thereon are often improved or modified during minor change periods, it is often necessary to alter the internal circuit construction of the electrical connection box and the connection construction of the electric devices in accordance with such improvements and modifications. When this happens, it is necessary to design and develop a new die and mold, which also undesirably increases cost.
Second, since the installation position of the electrical connection box 1 is restricted by the positions of the electric device mounting portions 1d and connector accommodating portions 1e provided on the upper case 1a, the degree of freedom of installation is low. Accordingly, efficient installation may be hindered.
Third, when electrically interconnecting the different wires constituting the wire harness W/H connected to the electrical connection box 1, a circuit portion which enables the electrical interconnection between the wires must be additionally formed in the internal circuit. This increases the number of circuits in the internal circuit, further complicating the circuit configuration.
Fourth, in the event where bus bars are employed in the internal circuits, since the bus bars are formed from sheet metal with a predetermined thickness, the weight of the internal circuits tends to increase. This problem is significant, especially when the internal circuits are formed by a plurality of bus bar layers.
The present invention overcomes the above disadvantages. An object of the present invention is to provide an improved electrical connection box that accommodates different vehicle types or design changes by selectively employing suitable common parts which, in turn, reduces cost. Another object of the invention is to increase the degree of freedom of installation of the electrical connection box to a vehicle body. This improves installation efficiency. Yet another object is to reduce the weight of the electrical connection box.
In a preferred form the electrical connection box includes an electric circuit board with internal circuits. The electric circuit board has connection portions. A plurality of blocks are mounted on the periphery of the electric circuit board, forming sidewalls that surround the periphery of the electric circuit board. The blocks mounted on the electric circuit board may be any of the following:
(a) at least one electrical component mounting block to accommodate an electrical component adapted for an electrical connection with the connection portion of the electric circuit board;
(b) at least one external circuit connection block to accommodate an electrical connector adapted for an electrical connection of an external circuit to the connection portion of the electric circuit board; and
(c) at least one solid, sidewall block to form a portion of the sidewalls.
In one aspect of the present invention, upper and lower covers are fixedly mounted to at least one of the selected ones of the blocks, covering the electric circuit board from above and below.
In a further aspect of the present invention, the electric circuit board has side edges on its periphery. The blocks each include a slit that opens to receive the side edge of the electric circuit board.
In a further aspect of the present invention, the connection portions are arranged side by side on at lease one of the side edges. The electric component mounting blocks and the external circuit connection blocks each include electrical terminals. The terminals are arranged side by side and engage the corresponding connection portions of the side edge for electrical connection when the selected ones of the electric component mounting blocks and the selected ones of the external circuit connection blocks are mounted to the side edges of the electric circuit board.
Preferably, the terminals include intermediate connection terminals. The terminals electrically connect contact portions of the electric components and the connector accommodated in the selected ones of the electric component mounting blocks and the selected ones of the external circuit connection blocks to the corresponding connection portions of the side edges of the electric circuit board. Also, at least one joint portion may be provided to electrically connect at least two of the intermediate connection terminals.
In a further aspect of the present invention, the electric circuit board is rectangular-shaped with four side edges on the periphery. At least four selected ones of the blocks are mounted to the four side edges of the electric circuit board, completely surrounding the entire periphery of the electric circuit board.
In a further aspect of the present invention, the at least four selected ones of the blocks are selected according to predetermined circuitry and structural constructions of the electrical connection box.
In a further aspect of the present invention, a plurality of selected ones of the blocks are mounted to the side edge of the electric circuit board. Each of the plurality of selected ones of the blocks has a length shorter than a length of the side edge.
In a further aspect of the present invention, the external circuit connection block has a connector accommodating portion at a first surface. The accommodating portion accommodates a first connector connected to a first wire harness which constitutes a first external circuit. A first slit is formed in a second surface which is disposed substantially parallel to the first surface. The first slit is dimensioned to receive the side edge of the electric circuit board in a first direction. A second slit is formed in a third surface which is disposed adjacent the first and second surfaces. The third surface extends substantially perpendicular to the first and second surfaces. The second slit is dimensioned to receive a first side edge of an auxiliary circuit board in a second direction substantially perpendicular to the first direction. One of the upper and lower covers has an external circuit connector port to accommodate a second connector which is connected to a second wire harness, constituting a second external circuit. The external circuit connector port has a third slit dimensioned to receive a second side edge, which is opposite to the first side edge of the auxiliary circuit board, in a third direction opposite to the second direction.
In a further aspect of the present invention, the external circuit connection block has an intermediate connection terminal. The intermediate connection terminal has three contact fingers. The first contact finger of the intermediate connection terminal is provided for electrical connection with a connection portion on the side edge of the electric circuit board. The second contact finger extends in a direction opposite to the first contact finger for electrical connection with a contact member in the first connector. The third contact finger extends in a direction substantially perpendicular to the first and second contact fingers for electrical connection with a connection portion on the first side edge of the auxiliary circuit board.
In a further aspect of the present invention, the selected ones of the blocks each include a plurality of slits spaced apart a predetermined distance in an upward-downward direction. A plurality of electric circuit boards are mounted to the slits so that the electric circuit boards are stacked and spaced apart at the predetermined distance in the upward-downward direction.
Preferably, the selected ones of the blocks each have a plurality of intermediate connection terminals. The terminals are arranged side by side and spaced apart at the predetermined distance in the upward-downward direction. At least one joint portion may be provided to connect at least two of the intermediate connection terminals. In a further aspect of the present invention, the electric circuit board includes a printed circuit board. Alternatively, the electric circuit board may include a bus bar.
In another preferred form, the present invention is directed to a method of producing an electrical connection box. The electrical connection box is produced by:
(a) providing an electric circuit board constituting internal circuits and having connection portions;
(b) preparing a predetermined number of different types of electric component mounting blocks to accommodate at least one electric component for an electrical connection with the connection portions;
(c) preparing a predetermined number of different types of external circuit connection blocks to accommodate at least one external circuit connector for an electrical connection with the connection portions;
(d) preparing a predetermined number of different types of solid sidewall blocks; and
(e) selectively mounting, to portions of the periphery of the electric circuit board, a plurality of blocks from among the electric component mounting blocks, the external circuit connection blocks and the sidewall blocks in accordance with predetermined circuitry and structural constructions of the electrical connection box. The plurality of blocks form sidewalls that completely surround the entire periphery of the electric circuit board.
In a further aspect of the present invention, the electric circuit board is produced for a particular vehicle specification accommodating the electrical connection box. The electric component mounting blocks, the external circuit connection blocks and the sidewall blocks are produced as common parts. Thus, the blocks can be selectively mounted to the electric circuit board in accordance with the particular vehicle specification.
From the following detailed description, taken in conjunction with the accompanying drawings and subjoined claims, other objects and advantages of the present invention will become apparent to those skilled in the art.